How did a 40-year-old woman who started out with just one restaurant come into such a vast fortune? I asked Peter Lewis, a professor of African Studies at Johns Hopkins University’s School for Advanced International Studies. He did not review the information about Isabel dos Santos’ holding and he said he didn’t know the specifics of Dos Santos’ wealth, but he did shed some light on how business is done in Angola: “It’s clear through documented work that the ruling party and the President’s inner circle have a lot of business interests. The source of funds and corporate governance are very murky,” Lewis explained. “The central problem in Angola is the complete lack of transparency. We can’t trace the provenance of these funds.”

In May 2012, she was reported to increase her stake in ZON Multimedia, Portugal’s largest cable TV company, from 4.9% to 14.9%. She later boosted her stake again via two of her shareholding companies, Kento and Jadeium, and now owns 28.8% of ZON, worth a recent $385 million. She sits on ZON’s board and is the company’s largest shareholder. The president’s daughter also owns 19.5% of Banco BPI, one of Portugal’s largest publicly traded banks. That stake is worth $465 million.